Candela Laser Corporation, in collaboration with scientists at the University of Chicago, proposes to develop a diagnostic instrument to measure the distribution of the lipoprotein fractions in blood plasma by gradient separations. The proposed instrument uses a fiber optic probe (optrode) to make in-situ UV absorption measurements of each class of lipoprotein separated by ultracentrifugation gradients. The separation method is an extension of the work of Scanu and others at the University of Chicago. The Phase II program will be to develop a second generation instrument based on the optrode concept demonstrated in Phase I, and to complete the development of the gradient separation in short spin times. The proposed instrument will be a valuable clinical diagnostic tool in the treatment of atherosclerotic cardiovascular disease.